The Ultimate Guide to SEO Redirects (301, 302, Chains)

Last Updated: October 25, 2025

Redirects are the essential plumbing of the web. They seamlessly guide users and search engine crawlers from an old URL to a new one, ensuring a smooth experience and, crucially for SEO, preserving link equity (PageRank). Whether you're undergoing a full site migration, moving content, changing URLs, or switching to HTTPS, a correctly implemented redirect strategy is non-negotiable.

However, choosing the wrong type of redirect or creating complex chains can severely damage your SEO performance by confusing search engines, diluting link equity, and wasting valuable crawl budget.

This guide provides a definitive overview of SEO redirects, focusing on the critical differences between 301 and 302 status codes, when to use each, how to implement them correctly, and how to diagnose and fix damaging redirect chains.

Chapter 1: Understanding Redirect Status Codes (301 vs. 302)

While there are several redirect status codes (3xx range), the two most important for SEO are:

• 301 Moved Permanently:**

  • Signal:** Tells search engines and browsers that the page has moved *permanently* to a new location.
  • SEO Impact:** This is the **gold standard** for SEO. Google interprets a 301 as a strong signal to transfer almost all link equity (PageRank) from the old URL to the new URL. It also updates its index to show the new URL in search results.
  • Use When:** The move is permanent (domain change, HTTPS migration, permanent URL restructure, consolidating duplicate content).

• 302 Found (or 307 Temporary Redirect):**

  • Signal:** Tells search engines and browsers that the page has moved *temporarily* to a new location. The original URL is still considered the "correct" one and should be used in the future. (307 is the HTTP/1.1 equivalent, generally preferred over 302 for temporary moves as it preserves the request method, but the SEO implication is similar).
  • SEO Impact:** Historically, 302s did not pass PageRank as effectively as 301s. While Google has stated they *can* now pass PageRank if they believe the 302 has been implemented permanently (often mistakenly), relying on this is risky. A 302 signals to Google to keep the *original* URL indexed, not the target URL.
  • Use When:** The move is genuinely temporary (e.g., A/B testing a new page design, redirecting users to a location-specific version temporarily, maintenance periods).

The Golden Rule:** When in doubt, use a **301 redirect** unless you have a very specific, temporary reason to use a 302/307.

Chapter 2: When to Use 301 (Permanent) Redirects

Use 301 redirects in these common scenarios:

• Domain Changes:** Moving from `old-domain.com` to `new-domain.com`.
• HTTP to HTTPS Migration:** Moving from `http://` to `https://`. See our specific HTTP to HTTPS Migration Guide.
• URL Structure Changes:** Changing your URL format (e.g., removing dates, adding subfolders).
• Consolidating Duplicate Content:** Redirecting multiple variations of a page (e.g., with parameters) to a single canonical version.
• Merging Websites:** Redirecting pages from an acquired website to relevant pages on your main site.
• Trailing Slash / Non-Trailing Slash:** Consistently redirecting one version (e.g., `example.com/page/`) to the other (`example.com/page`) to avoid duplication.
• WWW vs. Non-WWW:** Consistently redirecting one version (e.g., `www.example.com`) to the other (`example.com`).

Chapter 3: When (and When Not) to Use 302/307 (Temporary) Redirects

Use temporary redirects cautiously and only when the move is genuinely temporary:

• A/B Testing:** Temporarily redirecting a portion of users to a test variation of a page.
• Geotargeting (Use with Caution):** Redirecting users to a country-specific version based on location. hreflang is generally the preferred solution for this.
• Device Targeting (Use with Caution):** Sending mobile users to a separate mobile site (m.example.com). Responsive design is the modern, preferred approach.
• Short-Term Promotions:** Temporarily redirecting a product page to a special offer page.
• Site Maintenance:** Temporarily redirecting traffic while performing backend updates (a 503 Service Unavailable header might be more appropriate here).

Crucial Error:** Never use a 302 redirect for a permanent move (like changing domains or migrating to HTTPS). This confuses search engines and hinders the transfer of link equity.

Chapter 4: The Danger of Redirect Chains & Loops

• Redirect Chain:** Occurs when a URL redirects to another URL, which then redirects to a third URL (or more). Example: Page A (301) -> Page B (301) -> Page C (200).
  • Why it's bad:** Each "hop" in the chain wastes crawl budget. Googlebot might give up after a few hops. There's also potential for slight PageRank dilution at each step.
  • The Fix:** Update the initial redirect (on Page A) to point directly to the final destination (Page C). Page A (301) -> Page C (200).
• Redirect Loop:** Occurs when redirects eventually point back to a URL already in the chain, creating an infinite loop. Example: Page A -> Page B -> Page C -> Page A.
  • Why it's bad:** This completely breaks the user experience (browser shows an error) and makes the content inaccessible to search engines.
  • The Fix:** Identify the faulty redirect in the loop and correct it to point to the final, correct destination.

How to Find Chains & Loops:** Use SEO crawlers like Screaming Frog or Sitebulb. They have specific reports designed to identify redirect chains and loops across your entire site.

Chapter 5: Implementation Methods: Server-Side is King

How you implement redirects matters for SEO.

• Server-Side Redirects (Recommended):** Implemented directly on your web server. This is the fastest and most reliable method for search engines.
  • Apache (`.htaccess`): Uses RewriteRule directives (as shown in the HTTPS guide).
  • Nginx (`nginx.conf`): Uses rewrite or return directives.
  • Platform/CMS Level:** Many platforms (WordPress via plugins, Shopify, etc.) provide built-in interfaces for managing redirects. These usually implement server-side redirects behind the scenes.
  • CDN Level:** Services like Cloudflare allow you to implement redirects at the edge, which can be very fast.
• Client-Side Redirects (Avoid for SEO):** Executed in the user's browser, usually via JavaScript or Meta Refresh tags.
  • JavaScript Redirects (`window.location.href = ...`):** Google *can* sometimes process these, but it requires rendering the page, which is slower and less reliable than server-side redirects. PageRank transfer is uncertain.
  • Meta Refresh Redirects (`<meta http-equiv="refresh" ...>`):** W3C discourages their use. Google generally treats them like redirects, but they offer no advantage over server-side redirects and provide a poor user experience (page flashes before redirecting).

Rule:** Always use **server-side 301 redirects** for permanent moves to ensure optimal SEO performance and PageRank transfer.

Chapter 6: Redirect Mapping & Testing (SOP)

This ties directly back to the planning phase of any site migration.

1. Create a Comprehensive URL Map:** As outlined in the Site Migration Checklist, map every important old URL to its corresponding new URL.
2. Implement Redirects Based on the Map:** Systematically implement the 301 redirects according to your map.
3. Test Rigorously (Pre & Post Launch):**
   • Use a crawler (Screaming Frog list mode) or bulk redirect checker tool to upload your list of old URLs and verify that each one:
     • Returns a 301 status code.
     • Redirects directly to the correct new URL (no chains).
     • The final destination URL returns a 200 OK status code.
   • Test on staging first, then test immediately again after launch.
4. Monitor GSC:** After launch, watch the "Coverage" report in Google Search Console for any spikes in "Redirect error" or related issues.

Expert Insight (The Homepage Redirect Trap):
"A common, lazy migration mistake is redirecting large numbers of old, removed pages (404s) blanketly to the homepage using a 301. While this seems like it preserves 'link juice,' Google often treats these irrelevant redirects as **soft 404s**. This means they won't pass significant PageRank, and Google understands the content is gone. It provides a poor user experience. **Always redirect to the *most relevant equivalent* page.** If no equivalent exists, it's better to let the old URL return a 404 or 410 (Gone) status code."

Conclusion: Guide Users and Bots Correctly

Redirects are essential technical tools for maintaining SEO equity and user experience during website changes. Understanding the difference between 301 (permanent) and 302 (temporary) redirects, implementing them correctly server-side, and meticulously mapping and testing them during migrations are critical skills.

By mastering your redirect strategy, you ensure that both users and search engines are seamlessly guided to the right content, preserving your rankings and authority through any site evolution.